EXPLANATIONS AND REFERENCES, 



PLATE CXXXVTI. 



Figures magnified 250 diameters. 



PAGE. 

 Fig. 1-4. SPIROGYRA MAJUSCULA, . . . . .221 



Figs. 5, 6. SPIROGYRA BELLIS, . . . . . .217 



" 7, 8. SPIROGYRA NITIDA, ...... 217 



